I have wooden/aluminum clad crank out windows that are about
18 years old. A couple of the window seals have leaked and allowed the gas inside of the double panes to leak out causing condensation inside. A window repair shop in my area will repair the window by drilling a small hole in the inside glass, dry out the inside moisture and apparently refill the window with gas again and fill the hole. Has anyone heard of this method and does it work? I have 3 windows (1 large & 2 small) that have this problem and it is not feasible financially to replace the windows with new ones. Any info would be greatly appreciated. Thanks

 

I've know of this procedure, but it was usually done to IG units with defective spacer channels. Collapsed Glass is when atoms leak out from the spacer channel and nothing replaces these particles, therefore creating a vacuum. The two panes of glass bow inwards toward each other, sometimes even touching in the center in extreme cases. This causes a distorted hourglass image in the glass, and condensation to form on the interior of the home in a football or circular shape at the center of the pane of glass. However if you have a true seal failure then, to my knowledge, I do not think you can get rid of any water marks, or staining from between the panes. It is an effective procedure for collapsed glass which can be determined with a special tool which measures the distance between panes.

 

More than likely, the problem has nothing to do with the gas in your IGU. 18 years ago, I don't think they had gas filled IGU's, so yours are probably just air filled. The moisture means either the seal has failed, or the nitrogen dessicant inside the spacer has reached a saturation point, or both.

Pumping the moisture out would probably only be a temporary fix. In my opinion, the IGU should be replaced. That does not mean replacing the entire window, just the glass.

 

Good morning...

Whether your windows had a gas infill when first manufactured is really not an issue...despite what the repair shop apparently told you.

What grob62 did a really great job of describing is a totally different issue and one that can be repaired using the method that you and he described....but as he said, that is not really applicable in your case.

As you have already noted, your windows have a failed IGU spacer seal. This failure of the seal has allowed outside air to get between the panes of glass in the IGU (Insulating Glass Unit). The outside air has carried moisture with it when it entered the - no longer - sealed air space and when the air temperature between the panes goes below the dew point temperature of the air you will have condensation between the lites.

The glass shop has proposed drilling a hole to let the moisture out...but what about the original broken seal? They have said nothing about that, I assume, because there is nothing that they can do to fix the original seal leak other than completely taking apart the IGU and rebuilding it...a procedure that has its own long term problems.

If the glass shop has proposed filling the unit with gas, probably argon, that gas will very quickly be gone from between the panes - replaced by outside air again because of the broken seal. But (and one of the things that the folks marketing "window condensation repair kits" count on) that outside air will not immediately begin to condensate again...it will take a little while before it does so because of the nature of the original IGU manufacture.

When IGU's are manufactured with metal spacers, the spacer is filled with a desiccant material which absorbs moisture - the non-metallic spacer systems have desiccant as part of the make-up of the material. This desiccant keeps the airspace really dry which allows the temperature between the lites to drop well below zero without any condensation - simply because there is no moisture to condensate. When you have condensation between the lites due to a failed seal, the desiccant has simply absorbed moisture until it is saturated and it can no longer hold any more.

When the glass shop dries out the space between the lites, the desiccant will also be allowed to release the moisture that has brought it to saturation in the first place and it will again be able to absorb moisture that gathers between the lites. This will then allow the desiccant to absorb moisture as it enters the lite thru the failed seal - which was never repaired in the first place. For awhile, time dependent on how much moisture gets between the lites and how cold it gets, the window will look great...but eventually the desiccant will again be saturated and the window will again condensate between the lites. The money you spent was simply thrown away.

Unfortunately, there is no way to repair a failed seal. The only option is to replace the IGU. You don’t have to change the entire window, just the glass part.

But, not exactly good news, but not bad either, from an energy standpoint there is very little performance degradation between a sealed IGU and a unit that has lost its seal. The problem is primarily aesthetic. This does not apply directly to a unit that has a LowE coating or that was filled with argon, but in the case of 18 year old windows it is very unlikely this is the case. So while the condensation is annoying, it is not really costing you more on the heating bill.

And finally, another problem with the glass shops “repair” method, if there are water stains between the lites caused by the condensation, there is no way to get rid of them. Even after the IGU is “fixed” those stains remain.

 

XSleeper,

Your reply wasn't there when I started writing mine...so after I posted mine I read yours...

So tell me how is it that you said everything I said in only two lines when it took me a whole page to say it?

I can be verbose!

 

LOL. I had to get to work, so I was brief. I'll be the short version, you can be the long version.

 

thank you for all of your help, advice and time.